Current-limiting switch for electric lights.



PATENTED OCT. 25, 1904.

H. W. BROWN.

CURRENT LIMITING SWITCH FOR ELECTRIC LIGHTS.

APPLICATION FILED DEG. 3. 1901.

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No. 772,921. PATENTED 0OT.25,1904.

H. W. BROWN. CURRENT LIMITING SWITCH FOR ELECTRIC LIGHTS.

APPLICATION FILED DEG. 3. 1901.

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' No. 772,921. Patented October 25, 190%.

UNITED STATES PATENT OFFICE.

HARRY W. BROWN, OF WINCHESTER, MASSACHUSETTS, ASSIGNOR TO GEN- ERAL ELECTRIC COMPANY, A CORPORATION OF NEW YORK.

CURRENT-LIMITING SWITCH FOR ELECTRIC LIGHTS.

SPECIFICATION forming part of Letters Patent No. 772,921, dated October 25, 1904.

Application filed December 8, 1901. Serial No. 84,541. (No model.)

To all whom it may concern. may wind a piece of clockwork housed within 5 Be it known that I, HARRY W. BROWN, a a closed casing and closea short circuit around citizen of the United States, residing in Winthe switching devices, said short circuit being chester, county of Middlesex, State of Masmaintained for a prescribed time. Thus in 5 sachusetts, have invented certain new and case of an emergency when the consumer useful Improvements in Current-Limiting stands in strong need of more light he may Switches for Electric Lights, of which the folobtain the same by depositing a coin and oplowing is a specification. crating a control-handle, after which he may In installing incandescentlampssupply comuse as many lamps as he desires for a defi- I panics frequently wire aconsumers premises nite interval of timesay two or three hoursand furnish current on a contract basis by after which the short-circuiting switch will be which the custom r is permitted to burn a automatically thrown and the apparatus recertain maximum number of lamps, his house stored to its initial condition, all of the lamps being provided with enough lamps so that he being dimmed and the consumer forced either 5 can have suflicient light in any part of the to deposit another coin or turn off the extra premises. Thus it may be agreed that the lamps. 5 consumer is not to burn at any time more My invention therefore comprises an autothan ten lamps at once, although his house matic switch for dimming the lights on a conmay contain in the various rooms thirty or sumers premises in case an excessive number 20 forty lamps. In order to provide a check of lamps are burned at the same time. It

against dishonesty on the part 'of the concomprises also means for permitting an ex- 7 sumer, devices have sometimes been placed cessive number to be used for a determinate on his premises for breaking the circuit or time upon the payment of a coin or other preotherwise penalizing the customer in case scribed act, leaving a record for the supply 25 more than enough current to keep the agreed company.

number of lamps burning is used. Other features of novelty will be more spe- My invention relates to a system of this cifically hereinafter described and will be defitype,the object being to increase its flexibility nitely indicated in the appended claims. and afford the consumer greater convenience. The claims in the present application are 3 Systems of this type as heretofore proposed directed to the invention in combination with involve the extinguishment of the lights in prepayment devices or other means for govcase the prescribed number of lamps are exerning the lights in some prescribed way, ceeded or some other plan of forcing upon claims for the broader features of the inventhe consumers notice the fact that he is extion being embodied in a divisional applica- 35 ceeding the contract limit. tion hereof, Serial No. 1tO,97 6, filed on or I provide means for opening the switch and about January 29, 1903. 5 cutting in resistance on the lamp-circuit in In the accompanying drawings, Figure 1 is case the contract number of lamps are exa front view of an apparatus embodying my ceeded, thus dimming the lights and subjectimprovements. Fig. 2 is a diagram showing 4 ing the consumer to inconvenience and yet the circuit arrangements. Fig. 8 is a secpermitting suflicient illumination so that the tional view. Figs. 4, 5, 6, and 7 are views in 9 circuit-controller may be found and the damdetail of various parts. I age corrected. I provide also a prepayment Referring first to the diagram Fig. 2, 1 repdevice by which in case a greater than the resents the lamp-circuit in the consumers 45 number of lamps provided for by the contract premises, and 2 a solenoid in series relation is desired an unlimited amount of current to the circuit, provided with a movable core may be obtained by paying a coin of detercarrying a contact 3, normally short-circuitminate value through the prepayment device, ing a resistance I. Thus if the consumers and after inserting such a coin the consumer contract limits him to the use of five lamps in case more than this number are used at the same time the solenoid, which is calibrated to lift its core when six or more lamps are burning, opens a short circuit by way of contact 3 and cuts in the resistance L, thereby dimming the lamps and forcing the consumers attention to the fact that he is exceeding his rights under the contract. 5 represents an automatic switch, normally open, but which may be closed so as to short-circuit the coil 2 in case a definite prepayment is made, and 6 an auxiliary switch in the same short circuit, the purpose of which will presently appear. Thus by depositing, say, lifty cents within a closed casing provided with a door to which only an employee of the supply company has access, the consumer may operate a handle so as to close the contacts 5 and 6, as indicated in Fig. 2, thereby short-circuiting the solenoid 2 and permitting its core to drop and complete the lamp-circuit independent of the resistance &, and so long as the contacts are closed the consumer may use all the lamps with which the premises are equipped. These operations may be effected by many types of apparatus. One such type is shown in Figs. 1, 3, 4, 5, 6, and 7, in which 7 represents a closed cast-iron casing provided with a door 8, adapted to be secured by a seal, lock, or other contrivance which will permit access only of an employee of the supply company to the cash-box 9. The closed casing is provided with a coin-chute 10, the lower end of which terminates in a closed rotary section 10, containing a chute or channel which is large enough to freely admit transit of a fiftycent piece. This movable section is fastened to the winding-arbor of a clock-train 11, provided with an escapement, so as to mark time. Projecting through the casing is a windingstem 12, slotted, as indicated in Fig. 7, to admit the coin, and provided on the outside of the casing with ahandle 13, playing between two cast lugs on the door of the casing. \Vhen the handle is turned against the upper lug, as indicated in Fig. 3, the slot in the stem is in alinement with the chute in the movable section of the coin-duct, assuming that the apparatus is in an unwound condition, as indicated in Fig. 3. If now a fifty-cent piece be dropped into the chute or a coin of other determinate value for which the apparatus is constructed, it will fall until it assumes the position indieated in dotted lines, thereby locking the handle to the movable section of the chute and permitting the consumer to wind the clockwork for a definite range of movement. I prefer to design the parts so that the range of movement permissible to the handle will wind the clock to run about three hours. Itigidly connected with the winding-arbor of the clock is a pin M, adapted to engage a stud 15, projecting from a barrel 16,within which is housed a spiral spring 17. On the periphery of this barrel is mounted the spring-contact 5, re-

ferred to in the diagram Fig. 2, which closes a short circuit around the solenoid 2. This contact when the barrel is fully wound bridges two terminals 5 5" for the short circuit. The barrel is latched in this position when set by an offset 18 on the barrel, which is engaged by a spring-detent 19, secured to the casing. Thus it will be seen when the coin locks the handle and movable section of the coin-chute together and thehandle is turned the clock partly wound, and the pin 1&, engaging the stud 15, carries the barrel round against the tension of the spiral spring until the lug 18 is latched by the detent 19, at which time the spring-contact 5 will bridge the terminals 5 5". The short circuit is, however, not yet complete, since if left in this condition the consumer might fraudulently use current for any length of time without paying but a single coin. I provide, therefore, a means for preventing the short circuit around the solenoid 2 being closed until the operating-handle has been shifted back partly or wholly toward its initial position, thus insuring the spilling of the coin into the cashboX 9 and disconnecting the operating-handle from the clockwork. This may be simply and effectively accomplished by mounting on the key-stem 12 a movable trailer or bridging-contact 20, adapted to cross-connect two contacts 20 20", connected in a short circuit around the solenoid 2 when the handle is returned to its initial position. It is evident, therefore, that after operating the clockwork the consumer will have to shift the handle back to its initial position before the extra lights can be used, and until this is effected if more lights than are contracted for are connected in the circuit they can burn only at partial incandescence. On starting the handle, however, on its retrograde movement the pressure on the coin is released and the movable section of the chute having been shifted one hundred and eighty degrees from the position indicated in Fig. 3, the coin drops into the caslrbox 9. The movable section of the chute does not return then to its initial position untilthe clockwork has run down and brought the pin 21 against the lixcd stop 22. This section of the chute is then in alinement with the lixed section and a new coin can be deposited and the circuit again closed as before. hen, however, this position has been attained, the arm 14 will have reached the position indicated in Fig. 1, forcing open the latch between the lug 18and the detent 19 and permitting the barrel carrying the contact 5 to obey the impulse of the spiral spring, thereby rapidly snapping open the short circuit and putting the apparatus again under the control of the solenoid 2, which under the increase of current lifts its core and cuts in resistance 1, dimming all the lights. The core of the solenoid carries at its lower end a disk, bridging contacts 3 3", and l prefer to make these contacts yielding, so as to admit a rapid opening of the circuit when the solenoid leaves its core. They may, however, be mounted on journals, as indicated in Fig. 1, and placed side by side, as indicated in Fig. 3,the weight of the core being sufficient under normal strengths of current to strain the controlsprings, thus conducing to a rapid opening of the circuit after the core has acquired momentum. Thus it will be seen that if a consumer turns on more than the agreed number of lamps without paying for extra current the lamps will be dimmed, and he will be forced to cut off the extra lamp or put a coin into the prepayment device, by which he can have as much current as he desires.

What I claim as new, and desire to secure by Letters Patent of the United States, is

l. The combination of atranslating circuiton a consumers premises, a current-limiting switch inaccessible to the consumer to open the same on definite current-flow, and means under the consumers control for restoringthe circuit with increased current-flow in a predetermined way. I

2. The combination of a translating circuit on a consumers premises, a current-limiting switch to open the same on definite currentflow, and means for closing the circuit for a determinate time interval with increased current-flow.

3. The combination with a translating circuit, of a current-limiting switch to open the same on definite current-flow, coin-operated means for closing the circuit irrespectively of the current-flow, and timing mechanism for opening the coin-operated closure.

4. The combination of a consumers lighting-circuit, a current-limiting switch operated at a predetermined current maximum to penalize the customer, and a coin or token operated circuit-closer to permit current to be used above said maximum without penalizing the customer.

5. The combination with a consumers lighting-circuit, of a magnet responsive to the current-flow therein, a switch operated by the magnet at definite current value, a resistance cut into circuit to dim the lamps when the switch operates, a short circuit around the magnet, a coin-operated device for closing said short circuit, and timing mechanism for opening the short circuit again after adeterminate interval.

6. The combination, with a consumers circuit, of an automatic switch to cut off the supply at a predetermined current maximum, coin-operated means for insuring'a supply at or above said maximum, and a timing device for determining the period of current-flow at or above said maximum.

7 The combination with a consumers circuit, of an automatic switch for cutting off the supply of current at or above a predetermined maximum, a timing device governing the supply above said maximum, a closed casing, means for winding the timing device, and prepayment mechanism governing said winding means.

In witness whereof I have hereunto set my hand this 29th day of November, 1901.

HARRY W. BROWN.

Witnesses:

(J. N. MAsoN, CHAs. B. BURLEIGH. 

